[ISSUE apache#2421] Fix SelectMessageQueueByHash in case hashcode is Integer.MIN

Author: NeatGuyCoding

client/src/main/java/org/apache/rocketmq/client/producer/selector/SelectMessageQueueByHash.java

@@ -25,12 +25,10 @@ public class SelectMessageQueueByHash implements MessageQueueSelector {
 
     @Override
     public MessageQueue select(List<MessageQueue> mqs, Message msg, Object arg) {
-        int value = arg.hashCode();
+        int value = arg.hashCode() % mqs.size();
         if (value < 0) {
             value = Math.abs(value);
         }
-
-        value = value % mqs.size();
         return mqs.get(value);
     }
 }

client/src/test/java/org/apache/rocketmq/client/producer/selector/SelectMessageQueueByHashTest.java

@@ -44,6 +44,14 @@ public void testSelect() throws Exception {
         String anotherOrderId = "234";
         MessageQueue selected = selector.select(messageQueues, message, orderId);
         assertThat(selector.select(messageQueues, message, anotherOrderId)).isNotEqualTo(selected);
+
+        //No exception is thrown while order Id hashcode is Integer.MIN
+        anotherOrderId = "polygenelubricants";
+        selector.select(messageQueues, message, anotherOrderId);
+        anotherOrderId = "GydZG_";
+        selector.select(messageQueues, message, anotherOrderId);
+        anotherOrderId = "DESIGNING WORKHOUSES";
+        selector.select(messageQueues, message, anotherOrderId);
     }
 
 }